Field of the Invention
The present invention relates to a vehicle regenerative braking control device which comprises wheels that are braked/driven by a motor, which is capable of traveling by motor driving said wheels, and which is configured to cover for the braking force of the wheels with regenerative braking force of the motor.
Background Information
For example, as disclosed in Japanese Laid-Open Patent Application No. 1994-153315, braking of a vehicle can be summarized as a cooperative control in which a required target braking torque is obtained according to the driving state such as an accelerator release operation or a brake operation, and the running state surrounding the vehicle, during a coasting traveling in which the accelerator pedal is released or during a braking operation in which the accelerator pedal is released and the brake pedal is depressed, and in which said target braking torque is realized by combining the regenerative braking of the motor of the wheel drive system and frictional braking by a hydraulic brake or an electromagnetic brake.
The electric power that is generated by the motor by the regenerative braking is charged in a vehicle mounted battery, which is a power source of the motor, and thereafter used for motor driving. Upon the cooperative control described above, if the regenerative braking is preferentially utilized, and if the regenerative braking alone cannot achieve the target braking torque, it is common to employ a cooperative control method in which the target braking torque is realized by compensating for the shortage with frictional braking.
By configuring in the way described above, utilization of frictional braking can be suppressed to the minimum required amount by utilizing the regenerative braking as much as possible, having the maximum possible regenerative braking force determined by the charging state of the battery as the upper limit, and it is possible to minimize the frictional braking causing a loss of the kinetic energy of the vehicle as heat, while maximizing the amount of energy recovered to the battery, with the kinetic energy of the vehicle being converted into electric energy by regenerative braking. As a result, energy efficiency is improved, and fuel consumption rate as well as electricity consumption rate can be improved.